Abrading apparatus



Aug. 18, 1964 A. BLOCK 3,144,738

ABRADING APPARATUS Fiied March 6. 1961 km 16 l 14 ,lzfarmyr United States Patent 3,144,738 ABRADING APPARATUS Aleck Block, Los Angeles, Calif, assignor to Merit Products, Inc, Los Angeles, Calif., a corporation of Caiifornia Filed Mar. 6,1961, Ser. No. 93,505 6 Claims. (Cl. 51-1935) This invention relates to articles for providing an abrading action and more particularly to an abrasive article having a plurality of abrasive flaps and constructed to provide an abrasive action along the full surface of a blind hole. The invention is also concerned with novel apparatus for supporting members with an adjustable force, a plurality of flaps being one type of member which can be supported by such novel apparatus.

In modern industry, the need for providing polished surfaces in holes with precise tolerances is becoming increasingly urgent. For example, it is difficult to polish all of the surface defining a blind hole in order to obtain a desired cooperation between a first member including the hole and a second member fitting into the hole. Various abrasive articles have been used to polish the blind hole but such abrasive articles have not been entirely satisfactory since they have not been able to engage and polish the full surface defining the hole and particularly the portion of the surface defining the interior extremity of the hole. This has been especially true of abrasive articles formed from a plurality of abrasive flaps which are rotated against the surface to be polished. Such abrasive wheels have been unable to polish the portion of the surface at the interior extremity of the blind hole since the members used to support the flaps project laterally beyond the extremities of the flaps.

This invention provides an abrasive article which overcomes the above disadvantages. The invention is adapted to be used with a plurality of flaps each having an abrasive surface defined in part by first and second lateral edges and with means defining a hollow center and constructed to retain the flaps in an annularly stacked relationship. The invention is constructed to produce against the retaining means a force which can be adjusted-to any desired value. By producing the adjustable force against the retaining means in the annular direction, a support is provided for the retaining means and the flaps to obtain a rotation of these members.

The apparatus constituting this invention includes a sleeve which is disposed within the hollow center of the retaining means and which is made from an elastically expansible material. Means are included for producing an axial compression of the sleeve, this axial compression in turn producing a radial expansion of the sleeve against the retaining means. Themeans for producing such axial compression of the sleeve include a base member disposed within the sleeve and having a collar at one end of the sleeve. A threaded bore is provided axially in the base member at the end opposite to the collar and a screw, is adjustably inserted into the threaded bore. The screw is provided with a flanged head so that the sleeve becomes axially compressed between the collar and the flanged head.

The apparatus described in the previous paragraph is inserted into the hollow center defined by the retaining means such that it is interior of the first lateral edges of the flaps. In this way, the first lateral edges of the flaps define the lateral extremity of the abrasive wheel so that the abrasive wheel is able to engage the full surface defining a blind hole. The abrasive Wheel is able to be conveniently rotated since an arbor portion extends outwardly from the collar on the base member in a direction away from the support portion of the base P 3,344,738 c Patented Aug. 18, 1964 member. The arbor portion is provided with a threaded bore to receive the mandrel of a chuck.

Although the. apparatus constituting this invention has been developed primarily to support an abrasive wheel for rotation, it will be appreciated that it can be used in a number of other applications. For example, the apparatus constituting this invention can be used to support for rotation any other means in addition to an abrasive wheel. The apparatus can also be used to support means for movement in directions other than the annular direction.

In the drawings:

FIGURE 1 is a view, partially in section, of one embodiment of an abrasive wheel constituting this invention;

FIGURE 2 is a sectional view substantially on the line 22 of FIGURE 1;

FIGURE 3 is an exploded perspective view of certain members included in the embodiment of the abrasive wheel shown in the previous figures;

FIGURE 4 is a fragmentary perspective view which illustrates a plurality of flaps included in the abrasive wheel constituting this invention, one of the flaps being bent to indicate abrasive material on a surface of the fiap;and

FIGURE 5 is a view, similar to that shown in FIGURE 1, of a modification of the embodiment shown in FIG- URE 1.

In the embodiment of the invention shown in the drawings, a plurality of flaps generally indicated at 10 are provided. Each of the flaps 10 is preferably made from a thin sheet of a suitable material defined by a pair of oppositely disposed surfaces. An abrasive material 12 is disposed on one of the abrasive surfaces of each flap. The abrasive surface of each flap is preferably defined by a rectangular configuration having a bottom longitudinal edge 14 and a pair of lateral edges 16 and 18.

The flaps 10 are disposed in an annularly stacked re-r lationship with the bottom edges 14 of the fiaps being attached to an annular core which is generally indicated at 26 and which is provided with a hollow center. The core 26 is made from a suitable material such as cardboard and is provided with a bottom surface 28 and a pair of lateral surfaces 30 and 32. The bottom edges 14 of the flaps 10 rest on the bottom surface 28 of the core 26 and the lateral edges 16 and 18 of the flaps 10 respectively engage the lateral surfaces 30 and 32 of the A suitable adhesive such as an epoxy resin or a white vinyl glue may be used to attach the flaps 10 to the core 26. A suitable method of attaching the bottom edges 14 of the flaps 10 to the core 26 is fully disclosed and claimed in Patent 2,796,337 issued to me on June 18,

1957. It will be appreciated that other means than the core 26 and other methods than those disclosed and claimed in Patent 2,796,337 may also be used to retain the flaps in an annularly stacked relationship.

Means are adapted to extend into the hollow center of the core 26 to support the core and the flaps for rotations. Such means include a base member generally indicated at 40 and made from a suitable material such as steel. The base member 40 includes a support portion 42 having a cylindrical configuration and having a threaded bore 44 which extends axially into the support portion. An annular collar 46 is provided at the end of the support portion 42.

An arbor portion 48 extends axially from the collar 46 and has an axial bore 50 at the end opposite to the I collar 46. The bore 50 is threaded to receive a man- 'drel 52 and a threaded lock nut 54 which screws against 3 mandrel 52 extends from a chuck 56 which is rotated by any suitable drive motor.

A sleeve 60 is provided with an axial bore 58 and is push fit on the support portion 42 of the base member 40. The sleeve 60 is provided with an external radius slightly less than the radius of the hollow center in the core 26 and is provided with an axial length greater than that of the support portion 42 on the base member 40. The sleeve 60 is made from an elastically deformable material such as rubber so that the sleeve may be expanded radially against the core 26 to grip the core. The sleeve 60 becomes expanded radially against the core upon the exertion of a compressive force in an axial direction against the sleeve.

A screw 62 has a shank portion which threads into the threaded bore 44 in the support portion 42. The screw 62 also has a head which presses a washer 64 against the end of the sleeve 60. It will be appreciated that the washer 64 may actually be integral with the head of the screw to define a flanged portion. Since the sleeve 60 becomes compressed between the collar 46 and the washer 64 when the screw 62 is threaded into the bore 44, the sleeve becomes radially expanded against the core 26. This radial expansion can be controlled by adjusting the screw 62 in the threaded bore 44, the adjustment being provided by a suitable tool such as a Phillips Head wrench 70 in FIG- URE 1. In this way, a controlled supporting force can be exerted by the sleeve 60 against the core 26 to retain the flaps 10 for rotation with the mandrel 52.

The abrasive wheel shown in FIGURES 1 to 4, inclusive, and described above has certain important advantages. One advantage results from the fact that the lateral extremities 16 of the flaps 10 define the outer extremity of the abrasive wheel. By having the outer extremities 16 of the flaps 10 define the outer extremity of the abrasive wheel, the wheel is able to polish the complete surface of a blind hole including the portion of the surface near the interior extremity of the blind hole.

The abrasive wheel also has another important advantage. This results from the fact that the screw 62 can be adjusted in the bore 44 so as to produce corresponding adjustments in the radial force produced by the elastically expansible sleeve 60 against the core 26. In this way, the force for retaining the core 26 and the fiaps 10 during the rotation of these members in the blind hole can be adjusted to any desired value in accordance with the particular polishing work to be performed by the abrasive wheel. The production of a radial force by the expansible sleeve 60 for supporting the core 26 and the flaps 10 is also advantageous since the sleeve 60 is able to cooperate with the core 26 in opposing the shearing force produced against the core during the rotation of the wheel in a blind hole.

Another advantage results from the particular construction and relative disposition of the base member 40, the sleeve 60, and the screw 62. This results from the fact that the screw 62 is disposed at one end of the base member 40 and that the collar 46 is disposed at the opposite end of the support portion 42 of the base member. This allows the arbor portion 48 to extend from the collar 46 so as to provide a convenient coupling to a driving member such as the chuck 56. It will be appreciated that these advantages offer considerable opportunities for use in fields other than abrasive wheels.

FIGURE illustrates a modification of the abrasive wheel constituting this invention. This modification includes a base member generally indicated at 100 and corresponding substantially to the base member 40 in the previous figures. However, the base member 100 includes a lobe 102 on a support portion 104. The lobe 102 acts to press an elastically expansible sleeve 106 into a groove in a core 108. The sleeve 106 and the core 108 correspond substantially to the sleeve 60 and the core 26, respectively, in the previous figures.

Although this invention has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible for numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

I claim:

1. In combination for providing an abrading action, a plurality of flaps each having an abrasive material on at least one face of the flap, each of the flaps having a particular edge defining one extremity of the flaps, first means disposed in cooperative relationship with the flaps for retaining the flaps in an annularly stacked relationship defining a hollow center, there being an internally disposed groove in the first means, means made from an elastically expansible material for expansion into the groove in the first means and disposed within the hollow center defined by the first means for holding the first means and the flaps for rotation without extending beyond the particular edges of the flaps, and means disposed in cooperative relationship with the elastically expansible means for adjustably controlling the expansion of the expansible means into the groove in the first means.

2. In combination for providing an abrading action, a plurality of flaps each made from a thin sheet defined by a pair of opposite surfaces, there being abrasive material on at least one of the opposite surfaces in each flap, each of the flaps being defined by a longitudinal edge and first and second particular lateral edges, first means disposed in cooperative relationship with the flaps at the longitudinal edges of the flaps for defining a hollow center and for retaining the flaps in a stacked relationship during the operative movement of the flaps while retaining the first particular lateral edges of the flaps as the lateral extremity of the abrading combination, there being an internally disposed groove in the first means, means extending into the hollow center of the first means along the longitudinal edges of the flaps from the second particular lateral edges and made from an elastically expansible material for pressing against the groove in the first means in accordance with the expansion of the material to support the first means and the fiaps for operative movement, and means disposed in cooperative relationship with the expansible means at the end of the expansible means facing the first particular edges of the flaps for providing a controlled adjustment in the expansion of the expansible means.

3. In combination for providing an abrading action, a plurality of flaps each having an abrasive material on at least one face of the flap, each of the flaps having a particular edge defining one extremity of the flaps, first means disposed in cooperative relationship with the flaps for retaining the flaps in an annularly stacked relationship defining a hollow center, there being an internally disposed groove in the first means, means extending into the hollow center defined by the first means toward the particular edges of the flaps and made from an elastically expansible material and constructed for expansion into the groove in the first means to support the first means and the flaps for rotation, there being a bore in the expansible means at the end facing the particular edges, and means extending into the bore in the expansible means for adjustable positioning in the bore and provided with a construction to press against the expansible means with a force dependent upon the adjustable positioning of the adjustable means in the bore and to produce an expansion of the expansible means against the retaining means in accordance with the force exerted against the expansible means by the adjustable means.

4. The combination set forth in claim 3 in which a second bore is provided in the expansible means at the end opposite to the first bore to receive a mandrel for producing a rotation of the abrasive combination.

5. In combination for providing an abrading action, a plurality of flaps each having an abrasive material on at least one face of the flap, each of the flaps having a particular edge defining one extremity of the flaps, first means disposed in cooperative relationship with the flaps for retaining the flaps in an annularly stacked relationship defining a hollow center and provided with an internally disposed groove, a first member extending into the hollow center of the first means toward the particular edges of the flaps to support the flaps for rotation and made from an elastically expansible material for radial expansion into the groove in the first member in accordance with a force exerted on the member, there being a bore in the first member, a second member disposed within the bore in the first member and provided with a collar to press against the first member at the end opposite to that facing the particular edges of the flaps, there being a first bore in the second member at the end facing the particular edges of the flaps, and a third member adjustably positioned in the bore in the second member and constructed to cooperate with the collar to exert a force against the 6 first member in accordance with adjustments in the positioning of the third member in the first bore in the second member.

6. The combination set forth in claim 5 in which there is a second bore in the second member at the end opposite to the first bore to receive a mandrel for driving the abrasive combination.

References Cited in the file of this patent UNITED STATES PATENTS 2,556,684 De Santis June 12, 1951 2,593,735 Delzell Apr. 22, 1952 2,678,523 Leggett May 18, 1954 2,800,750 Field July 30, 1957 FOREIGN PATENTS 806,101 Germany July 8, 1949 

1. IN COMBINATION FOR PROVIDING AN ABRADING ACTION, A PLURALITY OF FLAPS EACH HAVING AN ABRASIVE MATERIAL ON AT LEAST ONE FACE OF THE FLAP, EACH OF THE FLAPS HAVING A PARTICULAR EDGE DEFINING ONE EXTREMITY OF THE FLAPS, FIRST MEANS DISPOSED IN COOPERATIVE RELATIONSHIP WITH THE FLAPS FOR RETAINING THE FLAPS IN AN ANNULARLY STACKED RELATIONSHIP DEFINING A HOLLOW CENTER, THERE BEING AN INTERNALLY DISPOSED GROOVE IN THE FIRST MEANS, MEANS MADE FROM AN ELASTICALLY EXPANSIBLE MATERIAL FOR EXPANSION INTO THE GROOVE IN THE FIRST MEANS AND DISPOSED WITHIN THE HOLLOW CENTER DEFINED BY THE FIRST MEANS FOR HOLDING THE FIRST MEANS AND THE FLAPS FOR ROTATION WITHOUT EXTENDING BEYOND THE PARTICULAR EDGES OF THE FLAPS, AND MEANS DISPOSED IN COOPERATIVE RELATIONSHIP WITH THE ELASTICALLY EXPANSIBLE MEANS FOR ADJUSTABLY CONTROLLING THE EXPANSION OF THE EXPANSIBLE MEANS INTO THE GROOVE IN THE FIRST MEANS. 